'If daughters of smoking mothers are more likely to grow up nicotine dependent, the result is a dangerous cycle of intergenerational transmission of nicotine addiction.'

Dr Stroud's team used data from 1,086 pregnant women enrolled in a health project that began in 1959.

The mothers had their hormone levels of cortisol and testosterone measured and smoking status recorded.

Dr Stroud said: 'While maternal smoking during pregnancy has been shown to be an independent risk factor for nicotine dependence, we did not really know which pathways or mechanisms were responsible. Most prior research involving biological mechanisms had been conducted in animals not humans.

'Our study suggests that maternal smoking and high stress hormones represent a 'double-hit' in terms of increasing an offspring's risk for nicotine addiction as an adult. Because mothers who smoke are often more stressed and living in adverse conditions, these findings represent a major public health concern.'

In female but not male offspring, exposure to nicotine and the stress hormone cortisol were associated with increased rates of smoking as adults.

Dr John Krystal, editor of Biological Psychiatry added: 'This new data may help us focus our attention on individuals at greatest risk for later smoking.

'It is interesting female, but not male, offspring seemed to be at greatest risk. Sex differences in the vulnerability to smoking are important and merit further study.'